Ruth L. Kirschstein, 83, a National Institutes of Health pathologist who helped develop and refine tests to ensure the safety of vaccines for polio and measles, organized the NIH response to the AIDS epidemic and became the first woman appointed director of an NIH institute, died Oct. 6 at the NIH Clinical Center in Bethesda. She had complications from multiple myeloma, a cancer of the bone marrow.

In 1955, a California pharmaceutical company, Cutter Laboratories, prepared several batches of the recently approved polio vaccine developed by Jonas Salk and inadvertently mixed live polio virus in with its vaccine doses. Ten children died, 200 developed varying degrees of paralysis and 40,000 became seriously ill.

As a result of the "Cutter Incident," Dr. Kirschstein, then a young doctor at NIH, played a vital role in developing an effective test to ensure the safety of the Salk vaccine and an oral polio vaccine developed by Albert Sabin.

In the 1980s, Dr. Kirschstein organized funding for and mobilized a team of NIH researchers to investigate the emerging AIDS epidemic and to seek possible treatments, despite vociferous opposition from some conservative lawmakers and lobbyists. When Dr. Kirschstein became director of the National Institute of General Medical Sciences in 1974, she provided critical support for work on the human genome by establishing GenBank, a nucleotide sequence databank.

She was deputy director of NIH in the 1990s and was twice appointed acting director, in 1993 and from 2000 to 2002. She then became a senior adviser to the director.

In an NIH video interview, Dr. Kirschstein recalled how her early life informed her later career.

"When I applied for medical school, women were not very commonly applying for school," she said. "I actually applied to every medical school in the United States. At least one of them wrote me and said, 'We only take men.'

"When I became the director of NIGMS -- the National Institute of General Medical Sciences -- people said, 'Well, you're going to hire only women,' " she said. "And I said, 'No. I'm going to give women an equal opportunity to men. But I don't believe in having an institute that's all men or all women. We are equal.' And so I did that, quite deliberately."

Ruth Lillian Kirschstein was born Oct. 12, 1926, in Brooklyn, N.Y., the daughter of a chemist and a public school teacher. She trained as a classical pianist but realized early in life that she wanted to be a doctor. She graduated from Long Island University in 1947 and received a medical degree in 1951 from Tulane University in New Orleans.

She joined NIH in 1955 as a resident in clinical pathology and laboratory medicine. From 1957 to 1972, she tested the safety of vaccines for measles and polio. She studied virally induced cancer in animals, which provided a basis for later cancer studies.

In 1972, Dr. Kirschstein became deputy director of the old Division of Biologics Standards, when it was transferred from NIH to the Food and Drug Administration. At the FDA, she worked on the safety of the artificial sweetener cyclamate before returning the NIH in 1974 as the first woman to direct an institute. During her 19-year tenure at the National Institute of General Medical Sciences, the institute supported the research of numerous Nobel laureates.

Dr. Kirschstein helped design programs to bring women and minorities into the biomedical sciences. Believing that science education could never start too early, she volunteered teaching the subject at an elementary school in the District's Anacostia neighborhood.

She led a comprehensive study of the peer-review system under which NIH research grant applications are evaluated, strengthening the support for creative research and young investigators.

For her work on vaccine testing, she received superior service awards from the Department of Health, Education and Welfare and the U.S. Public Health Service. In 1985, she received a Presidential Rank Award of Distinguished Executive, the country's highest civil service honor.

In 2002, Congress renamed the NIH graduate student fellowship program for Dr. Kirschstein. She was a member of the Institute of Medicine and a fellow of the American Academy of Sciences.

Survivors include her husband of 59 years, Dr. Alan S. Rabson of Bethesda, a pathologist and a deputy director of the National Cancer Institute; a son, Dr. Arnold Rabson of Princeton, N.J.; and a granddaughter.